What is the cold sink that caused the bad floods in Spain?

These are the worst floods of this century in Spain: they have killed almost a hundred people and the destruction in some places in the south-east of the country is terrible. How could the storm be in such a real form?

The culprit is a so-called cold sink, explained NOS meteorologist Marco Verhoef. “High in the sky, at an altitude of about 5 kilometers, there is a bubble of cold air in a low pressure area. sorry to leave.”

In Spain the phenomenon is called DANA: Isolated depression at high levels, or ‘isolated depression at higher levels’. And because that depression is closed, it will stay in about the same place and take water.

Meteorologist Marco Verhoef explains how the DANA weather phenomenon works:

In that cold pit, at an altitude of 5 kilometers, it is colder than 20 degrees below zero, while the water of the Mediterranean Sea is currently warmer than 20 degrees. “That big temperature difference creates strong vertical air currents, which can quickly form huge rain clouds. A lot of rain can fall in a short period of time, especially in a mountainous area.”

Precipitation amounts varied greatly by location. In one place, more than 400 millimeters of precipitation was measured, which is about half of what is in the Netherlands in a whole year.

This map shows how rainfall fell in parts of Spain on Tuesday only:

In addition, much of the rain fell in a part of Spain that is usually very dry. In the southern half of Spain there is almost no rainfall during the summer months. Water is hardly absorbed by a dry surface, so it simply flows over it. In the mountainous region, large water flows occur after a heavy downpour.

Couldn’t see this disaster coming? Verhoef: “That low pressure area was indeed in the weather models. But you can hardly see the number as big, which is also locally coming. There are places where 300 millimeters fell, and two town away just 11 millimeters.”

As the earth becomes more common, these types of weather become more common. The water in the Mediterranean Sea was warmer than ever this summer: a water temperature of 28.47 degrees was measured in August. This month the water is much warmer than usual. This also causes the showers to become more intense, says Verhoef, who has seen this happen in the past few days: “That warm water kept giving new energy to the system that weather.”

The rain is not gone yet. Weather warnings are still in effect in Spain. In the coming days, the low pressure area will gradually move west and become a bit more active. There may still be heavy showers in the country, but the weather should calm down over the weekend.